Paper Title (use style: paper title) - ER Publications€¦ · Web viewInternational Journal of Enhanced Research in Science, Technology & Engineering. International Journal of

International Journal of Enhanced Research in Science, Technology & EngineeringISSN: 2319-7463, Vol. 5 Issue 1, January-2016

IDENTIFICATION AND CHARACTERIZATION OF MORTARS IN THE OTTOMAN ERA IN ALGERIA THROUGH LABORATORY ANALYSES AND THEIR COMPARISON WITH STUDIES OF HISTORICAL DOCUMENTATION

Naima Abderrahim Mahindad1, Messaoud Hamiane

1Corresponding Author, ENCRBC, Research unit of the mineral and composite materials, University M’Hamed Bougarra, Faculties of Engineering, Boumerdes, Algeria.

Email: [email protected] Messaoud Hamiane, University M’Hamed Bougarra, Faculties of Engineering, Boumerdes, Algeria

Email: [email protected]

ABSTRACT

In the Algerian traditional and historical architecture, there are a variety of mortars which were used for jointing and coating. Although Algeria conceals a very rich patrimonial park, our interest is mainly focused on the mortars used in the buildings in the Ottoman Era, in Algeries. Through the last researches which based on specific historical documentation of the Ottoman Empire, which is constituted by the archives of Ottoman administration, we have information for the used materials, the manufacturing of various mortars and especially their implementation. The aim of the present study is to identify the physical and chemical properties of Ottoman mortars in Algiers as part of an investigation into the mineral raw materials present in the territory of Algiers and to determine their chemical and mineralogical compositions. These results will be compared with information reported on recent research that rely on the documents of the Ottoman archives.

Keywords: Algeries; Characterization; chemical composition; Historical documentation; Lime mortars; mineralogical composition; Physical properties..

1. INTRODUCTION

Knowledge of materials, is an important source of information for understanding the evolution of The mortar dating from the ancient period, and to find the characteristics of a mortar compatible with older mortars that can be used in the restoration of historical monuments.

The problem of formulating mortars for restauration has become increasingly important in the last decade. Restoration mortars must be prepared to take into account the characteristics of the materials to which they are applied or they substitute [1]. In the operation of restoration or reconstruction, it is convenient to characterize the mortar on its morphological appearance and physical, so that the new mortar does not differ from the old [2].

The ancient mortar, including "Roman concrete" was the reference mortar which is perpetrated through the ages arts in society and for the conservation of heritage objects [3]. Mortars of different types and compositions were widely known and used in the ancient world and the lime mortar was throughout the Roman Empires. In many cases lime was used as a binder and for better plasticity [4]. Roman mortars have been highly appreciated for their durability. Hence, their physico-chemical and microstructural characteristics have been widely investigated [5].

In recent decades, the research of masonry binders was interested in the characterization of materials [6] . These new investigations opened the field to new knowledge and perception of the material through a scientific and analytical approach.

The compilation of the studied mortar groups confirms that there were, in the past, traditional mortar technologies that remained unaltered for large historical periods. The properties of crushed brick mortars, for example, do not show appreciable changes from the early Byzantine to the late Ottoman period [7] .

In Algeria, studies relating to the mortar, to Ottoman period are very rare and only covers a small part of its heritage: Building materials from the Ottoman period in Algeria were studied through an original documentation exploited in recent research of S.Chergui [8] and A. Foufa [9]. This documentation consists of the archives of the Ottoman period, it identifies the different materials used at the time as well as construction techniques and implementation, which revealed all the local knowledge and the mastery of all the time builders.

Ottoman’s mortars are an ancient binding material (lime mortar), that was used for centuries in historical buildings in Algeria, there are a variety of mortars which were used as: jointing and coating mortar.

Page | 1


The aim of this study is to establish the characteristics of ancient lime mortars, used in Ottoman’s building in Algiers, and identify their compositions and techniques and compare the results to the different historical information reported in the studies that were based on documents from the Ottoman archives. Samples of mortars were collected and described in situ, and a number of laboratory tests were carried out to determine their physical properties, chemical and mineralogical composition. The exploitation of the results of these researchers, allowed us to identify all the materials used for preparing mortars and their different applications.

The diversity of the Ottoman buildings varies according to their size and their geographic locations. In our study, we had to limit our investigations to the most representative buildings in the city of Algiers. The following buildings were selected (Fig.1)

. Fig. 1. Location of samples:a/b: Site of samples MJ1 and MC1: Powder keg; c/d: Site of samples MJ2 and MC2: Casemates; e/f: Site of samples MJ3 and MC3:

Casbah of Algiers; g/h: Site of samples MJ4 and MC4: Villa Mahieddine

- Citadel of Algiers: the seat of Ottoman power, made up of various structures: the Palace and Mosque of the Dey, Bey Palace, Summer Pavilion, the bath (Hammam) of the Dey, District of Janissaries, Skifa, casemates and a powder magazine. The construction of this set was between the XVIth and XVIIth century

- Casbah of Algiers: The Medina, which is the city through its minor Ottoman architecture (the houses), all designed from the XVIth to the XVIIIth century.

- Villa Mahieddine: It is a Fahs house (outside the Medina and the ramparts), it is a villa, mostly used in summer, it was built between the XVI and XVII century.

2. MATERIALS AND METHODS

A. Materials

Page | 2


The mortar can have multiple uses such as jointing of masonry, finishing, coating and sealing for the terrace. In this study, we were interested in jointing and coating mortar (plaster) used at the various sites previously mentioned.

In this study, we performed the sampling of 08 samples of jointing and coating on the various sites we have exposed. These mortars present visual differences in their colors and texture.

Jointing mortars

a- The Citadel of Algiers: one chose two samples of mortar of jointing:

The powder keg (MJ1): It is a yellowish mortar strewn with large quantities of lime particle size more or less important. It also contains grains of rubble, but not much. It is a friable material by hand, but crumbled, the resulting particles are more or less large (Figure.2a).

The casemates (MJ2): it is a reddish mortar of color brownish strewn with lime grains moreover at least great dimension. This mortar is very friable with the hand and present at the naked eye a great number of pores. Crumbled, it is composed of very fine particles of ground (Fig.2b)

b- Casbah of of Algiers (MJ3): It is a pinkish color mortar, very compact but friable with the hand. Crumbled, and one raises the presence of lime traces of whitish color in much reduced quantity. It also presents to the naked eye a certain number of pores (Fig.2c).

c- Domain or“Djenane” Mahieddine (MJ4): It is a pinkish color mortar see reddish-dense (very compact) seemingly but friable with the hand. It presents some brown spots (in much reduced quantity) and small grains of lime. Crumbled, it is composed of very fine ground (earth) and fine sand particles and presents to the naked eye a certain number of pores

(Fig.2 d)

Fig. 2. Macroscopic observation of different samples

Coating mortars

a- The Citadel of Algiers: one chose two samples:

The powder keg (MC1): It is a mortar of very clear orange- pink color, strewn with brown, but very scattered spots and lime particles at least large in great quantity. It is a material friable with the hand and presents to the naked eye a certain number of pores (Fig.3.a).

The Casemates (MC2): It is a mortar of very clear pink color to see a whitish, spotted with brown, but very scattered spots and lime particles at least large in great quantity. It is materials compact and porous (Fig3. b).

b- The Casbah of Algiers: The mortar of coating, raised (MC3) presents a color very moderate which vary between the yellow, pink color and white by place what let’s suppose a variety of the components. This mortar is strewn with brownish red spots and lime grains at least large significant amount. It is a material friable with the hand, and porous. Crumbled, it presents grains of various dimensions and even the broken stones (Fig3. c).

c- Villa Mahieddine (MC4): The first part of a significant thickness of up to 2 to 2.5 cm of pink - reddish. It is strewn with brown spots of various dimensions and in significant amount as well as lime particles at least large. It is very friable with the hand and presents certain numbers of pores visible with the naked eye (Figure3.d).

Page | 3


Fig.3 Macroscopic observation of different samples of coating mortars

B. Methods

We opted for complementary analytical techniques for chemical and mineralogical characterizations the mineralogical. The advantages of this method are based on the fact that the various observations directly provide a lot of information. Combining these observations with physical and chemical analysis techniques allowed us to identify non-observable elements and control and validate some of the first observations and to obtain optimum understanding of the materials

1 Physical properties

European EN 1936 [10] is used for the determination of basic physical properties, such as bulk density, apparent porosity and moisture content of mortars. The determination of the concentration of free lime (Cao) is based on the solubility of calcium oxide and hydroxide in a sucrose solution. The volume of hydrochloric acid required for neutralization of the alkaline solution of calcium, determines the content of free lime. The Rate of the organic mass Cmoc is determined according to the French standard norms XP P 94-047: this test can determine the mass loss of a previously dried sample in an oven at a temperature of 450 °C.

2 X-ray powder diffraction analysis

Mineralogical analysis (XRD) concerns the identification and determination of the constituent minerals of the material and to develop a quantitative estimation was carried out by X-ray diffraction following procedure, drift in the user manual and software X PERT DATA COLLECTOR.

3. Chemical assessment methods

The chemical composition of the Ottoman mortars was determined by X-ray fluorescence spectrometry using the principle of the NF P 15-467, presented in weight percentage. The loss on ignition was determined at 1000 °C, in the manner of EN 1744-1. Hydraulicity and cementation indices were recalculated using equations (1) and (2) [11].

HI= Al2O3 %+Fe 2O 3 %+SiO 2 %CaO %+ MgO %

(1)

Page | 4


CI=1,1 Al2O3 %+0,7 Fe 2O 3 %+2,8 SiO 2 %

CaO %+1,4 MgO % (2)

3. MORTARS OF OTTOMAN ERA ACCORDING TO HISTORICAL SOURCES AND ARCHIVE DOCUMENTS

S. Chergui [8] has identified in the ottoman archive, known “habus documents”, the Mortar called, in the local dialect"Baghli" or "Khumra (Chergui, 2010). It is a lime-based binder. The great qualities of the binder permitted different constructions of walls, but also arches and domes. The mortar could have had multiple applications, i.e. jointing, grouting or filler, but the basic components remained the same: sand and lime. To this mixing, were added other components such as broken tiles or crushed bricks.

The materials which composed the ottoman mortars, are drawn of geological formations of the city of Algiers. According to R. LESPES [12], mortar was composed of red sand argillaceous of Pliocene formations, mixed with greasy lime. The mortar of the Ottoman Empire was composed of lime and red clay from land-flood [13]

These materials were taken from near the city career: In the North and North West of Algiers, there were a career called career of hydraulic works, which consists of a crystalline limestone and near which we find a mass of clayey marl and sand which gives very good mortars [8].

Mortar is a binder composition (lime) and Degreasers (sand and additions), mixed with water: Masons extract limestone quarries of lime and conduct calcination in furnaces designed for the purpose near the quarries.Then they proceed to the extinction of lime, at construction sites [14].

S. Chergui based on the bookkeeping records of Ottoman archives mentions the use of two types of lime, the first called “Djir Ghabra” that means, the lime powder characterizing the quicklime and the second “Djir Dhars”, that means, the slaked lime. She reports that the book which refers to the years 1735-1738, states that a quantity of quicklime was slaked directly on the site. These two types of lime were used in various operations such as: rough casting (plaster) or restoration or the painting. Mortar was made according to precise proportions (A portion of lime for two to three parts sand), the grain sizes largely depended on the use of mortar, i.e. bedding or coating, the use of one part of coarse sand for the mortar of fillings and the fine sand for rough casting was mentioned in the records [8]

4. RESULTS AND DISCUSSION

1. Physical properties

Data on the physical properties are shown in Table1. For the jointing mortars, MJ3, contains brick fragments and crushed ceramics and is observed to have the highest hydraulicity and cementing coefficients. According to the water absorption data, specimen MJ3, also has the lowest porosity value and the highest HI and CI indices. In comparison, MJ1 containing brick and limestone fragments attained the highest porosity and the lowest HI and CI indices.

For the coating mortars, specimen MC1 has the lowest HI and CI indices, conversely, it has the highest rate of absorption and porosity

Page | 5


Table1. Physical propreties of mortars

2 Mineralogical composition

XRD analysis (Tab 2), revealed the presence of significant amounts of quartz and calcite in the all samples of mortars and the small quantity of Muscovite and Albite. We revealed the presence of a low proportion of Kaolinite, only in MJ1 specimen. The other components are in smaller amounts.

Table2. Results of XRD analysis

3. Chemical composition

Page | 6


The results of the chemical analyses are given in Table 3, Hydraulic properties of mortars were determined by calculating hydraulic (HI) and cementation (CI) indices considering the chemical compositions of white lumps according to Boynton formula (ex. (1) and (2)), the highest values for the hydraulicity and Cementation indices correspond to a higher SiO2, Al2O3 and Fe2O3 content. Table 4 illustrates that the above values are higher for specimen MJ3, for jotting mortars and specimen MC4, for coating mortars. The results reveal remarkably uniform compositions for mortars from very different structures.

Table3. Chemical composition of the mortars Xt (%)

5. DISCUSSION

A. Jointing Mortars: The results concerning the tests of physical characteristics summarized in Tab.1 show that the average value of apparent density is 1,57g/cm3. The gap between the density’s maximum and minimum values is 0,25g/cm3. The average value of the absolute density is 2,12g/cm3, of which the gap between the maximum and minimum values is in the range of 0,36 g/cm3.

At the base of the values of the absolute and apparent densities, the total porosity has been calculated and the average value was 28,27%. A result which involves a high rate of water absorption and was confirmed by the results and its values were ranging from 12,75% to 20,18%, thus indicating a significant presence of open pores.

The chemical analysis shows the composition of different samples of bedding mortars in the city of Algiers, points out a high proportion of silica in SiO2 hydrated form, whose origin can be quartz or clay; There are also significant proportions of calcium oxide CaO (quicklime) yet substantially less than the amount of silica. Significant quantities of alumina (Al2O3) are also pointed out, while the other components Fe, Na and K are present in more moderate amounts.

The results of the loss in ignition, give values ranging from 15,30% for the Casbah of Algiers (MJ3), to 19,49% for Casemates (MJ2), and this indicates the rate organic matter and organic carbon content of the sample. In addition, all studied samples contain phosphorus pentoxide (P2O5) in small quantities. This component (phosphorus) is an essential constituent of the organic matter and is an indispensable nutrient to living organisms, so, it has its origin in organic materials. The latter may be an organic additive used in the manufacture of the mortar as mentioned in historical writings or it was contained in the raw materials that constitute the mortar, therefore, it has been extracted from geological deposits, which supplied the materials of construction, for the building sites, in the city of Algiers, in the Ottoman era

The mortar XRD analysis identifies many crystalline phases. The most inherent minerals are quartz (SiO2) and calcite (calcium carbonate). In all the samples, the presence of small amounts of Albite and Muscovite is pointed out and which source is probably crushed or cracked fragments of bricks and ceramics added to the mortar. The sample MJ1, drawn from the powder keg shows that the mortar of this building contains the Kaolinite, which is a clay mineral found in the manufacture of ceramics, while the other three samples are enriched in clay materials.

Different mineral compositions confer significant hydraulicity and cementing coefficients to all samples: HI hydraulicity index is inversely proportional to the absorption of water content as we can see in the Tab.3, where the sample MJ3, has the lowest porosity and water absorption values is the highest HI and CI indices. In comparison, the sample MJ1 (powder keg) containing fragments of brick and limestone reaches the highest porosity and the lower HI

Page | 7


and CI indexes. Hydraulicity and cementing of the samples depends on the porosity of mortars and used additives (ceramics, crushed or cracked brick).

B.Coating Mortar

The results of physical tests summarized in the Tab.1 show that the average value of apparent density is 1,64g/cm3. The gap between the density maximum and minimum values is 0,33g/cm3. The average value of the absolute density is 2,23g/cm3, of which the gap between the maximum and minimum values is of the order of 0,46 g/cm3.

The total porosity calculated based on values of apparent and absolute densities, gives an average value of 26,60%, which indicates absorption rates ranging from 13,53% to 18,84%.

Like bedding mortar samples, the chemical analysis reveals, within the composition of the various samples of finishing mortars of the city of Algiers, a large proportion of silica in hydrated form SiO2 whose origin can be quartz or clay and less important proportions of calcium oxide CaO (quicklime). Furthermore, all other components and notably alumina (Al2O3) are present in small quantities.

The results of the loss in ignition, give values ranging from 10,33% for the villa Mahieddine (MC4), and 19,07% for the casemates (MC2), indicating the sample’s organic matter rate and organic carbon content.

P2O5 contents are very tiny and the largest content was 0,12% in the sample MC3 from a building in the Casbah of Algiers. This mineral was inadvertently found in the composition of mortars and probably came from the raw materials used in the manufacture of mortars and extracts of geological deposits around the city of Algiers.

The XRD mineralogical analysis allowed the identification of various crystalline phases. The most present minerals are quartz (SiO2) in proportions ranging from 41% of the sample MJ1

(powder Keg) and 57% of samples MJ2 (Casemates). The contents of calcite (calcium carbonate) of the samples are of the same order as the quartz contents, but in reversed proportions, that is to say that samples with high contents of quartz, their calcite content is less important: The sample MJ1, that has a quartz content of 57%, its calcite content is 24%, while the sample MJ1, has equivalent contents of SiO2 and calcite (respectively 41 and 44%). It is noted for all the samples, the presence of small amounts of Albite and Muscovite, whose source is probably dried brick and crushed or cracked ceramic added to mortars.

The presence of clay materials was found in two samples MJ3 (Casbah) and MJ4 (Villa Mahieddine).

Different mineral compositions (Tab.2), confer significant hydraulicity indices and cementing to all samples: The Indice of hydraulicity (HI) and cementing (CI), index are important in all samples, ranging from 2,21 for HI and 9,06 for CI, in the sample MC1 (powder keg), to 4,88 for HI and 11,77 for CI, in the sample MC4 (Villa Mahieddine). While the other components show only small amounts of more than 6%, particularly Muscovite whose origin is generally additions of ceramic and fragments of crushed or cracked bricks, otherwise, no presence of clay material has been pointed out. This findings allows us to state that the amount of additions of ceramic elements and brick affects hydraulicity and cementing of mortars.

6. CONCLUSION

The following conclusions can be drawn from this study on the analysis of physicochemical properties of the building's masonry in the city of Algiers during the Ottoman period.

The fragments of ceramics and crushed brick, organic materials, the presence of mineral Muscovite, recrystallized calcite as well as the porosity degree and the pore distribution in the matrices of mortars are probably responsible for the level of hydraulicity and the cementing of mortars.

The chemical analysis has indicated that the oxide composition of mortars, concerning the Ottoman buildings in the city of Algiers, is generally composed of a large amount of Si, Ca and lesser amounts of Fe, Na and K.

The high contents of SiO2 + Al2O3 + Fe2O3 are probably responsible for the major indexes of hydraulic and cementing in all samples.

The samples MJ3 for the jointing mortars and MC3 for coating mortars have the greatest hydraulic and cementing indices and the lowest water absorption and porosity, these results are probably due to their crushed ceramic content of both samples of mortars. However, the mortars with more significant limestone contents gave inferior results.

All these results enabled us also to find similarities in components of mortars and their respective proportions, despite the diversity of sites and buildings, leads us to say that there was a common knowledge of the builders, in the city Algiers, perpetrated for centuries as these buildings were made between the sixteenth and the eighteenth century.

Page | 8


These mortars are made up of lime and clay as stated in historical documents and archives. The compositions of these mortars, are made according to precise proportions of these components: the most important component in terms of quantity is quartz and feldspar found in siliceous sand or clay used as a degreaser, then the quicklime used as binder. These same components have been reported in historical and archives documents of the Ottoman period, which reported in recent research.

7. ACKNOWLEDGMENT

The authors are thankful to Centre for Studies and Services Technology Industry of Building Materials, at Boumerdes and the National Office of Geological and Mining Research, for providing assistance in carrying out the tests.

REFERENCES

[1] P.Rota Rossi-Doria. “Mortars for restoration basic requirements and quality control”, in Materials and structures, Novembre 1986, Volume 19, issue 6, pp 445-448

[2] Ashurst, J. Mortars, “plasters and renders in conservation”, Ecclesiastical Architects' and Surveyors' Association (1983).[3] S. Büttner et D. Prigent, “Archéologie des liants de maçonnerie : entre traités et réalité, dans medieval Europe”, Paris 2007, 4 eme congrés

international, d’archéologie medievale et moderne, 2007 (publication electronique), http://medieval-europe-paris 2007.univparis1.fr/S.B%C3%BCttner%20et%20al..pdf

[4] S. Kurugöl, A. Güleç, “Physico-Chemical, Petrographical and Mechanical Properties of Mortars used in an Ancient Roman Basilica in Amasra/Turkey” , Gazi University Journal of Science, 2015file:///C:/Users/admin/Downloads/1060001842-5000269739-1-PB%20(1).pdf

[5] R. Mallinowski, “Durable préhistorique ancient mortars and concretes, Nordic Concrete Research, in transportation research board”, décembre 1982, p22

[6] A. Coutelas, “Pétroarcheologie du mortier de chaux gallo-romain. Essai de reconstitution et d’interpétationdes chaines opératoires : du matériau au métier antique”, Archives ouvertes HAL, 2003, https://tel.archives-ouvertes.fr/tel-00528508/file/Coutelas_2003.pdf

[6] Palazzo-Bertholon. “Histoire, archéologie et archéométrie des mortiers et des enduits au Moyen Âge”, Thèse de doctorat, Lyon II - Louis Lumière, Lyon, 1998.

[7] H. Binici, J. Arocena, S. Kapur, O. Aksogan, H. Kaplan, “Investigation of the physico-chemical and microscopic properties of Ottoman mortars from Erzurum (Turkey)”, Constr. Build. Mater., 24 (10) (2010), pp. 1995–2002.

[8] S. Chergui , “To build, manage and preserve their Al-Djaza'ir mosques Ottoman (XIV the-XIX th century)”, Sorbonne, Paris, 2010.[9] A. Foufa, “Contribution to the discovery of earthquake - resistant techniques adopted in the large cities of the Maghreb (Algeria, Fez and Tunis)

during the XVIII century " (2007), PhD Thesis, Algiers, Épau[10] European Standard EN 1936, “Natural Stone Test Methods. Determination of Real Density and Apparent Density, and of total and open Porosity”. Brussels, December 2006[11] R.S. Boynton, “Chemistry and Technology of Lime and Limestone”, Wiley, New York ,1980[12] R. Lespes, “Study of geography and urban history”, Algiers, 1930[13] CA. Rozet, “travel in the regency of Algiers,” 3 Flight, 1833, Paris[14] Adams.J.P,The “Roman construction materials and techniques, publishing sciences”, Great Picards manuals, 2011.

Page | 9

https://tel.archives-ouvertes.fr/tel-00528508/file/Coutelas_2003.pdf

Documents

Paper Title (use style: paper title) - ER Publications€¦ · Web viewInternational Journal of Enhanced Research in Science, Technology & Engineering. International Journal of